(a) Field of the Invention
The present invention relates to a method of treating tobacco by expressing protoplasmic juices from green tobacco and thereafter artificially curing the tobacco, thereby altering the tobacco's chemical composition. Optionally the expressed juices may be processed and reapplied to the tobacco to further control the chemical composition of the tobacco.
(b) State of the Art
Alteration of the chemical composition of tobacco to thereby modify the smoking characteristics and/or combustion products of smoking tobacco products is known in the art. A common means to effect such alteration involves extraction of soluble constituents of cured tobacco, possibly followed by treatment of the tobacco extract to selectively remove constituents thereof and reapplication of the thus treated extract to a web of extracted tobacco.
Extraction of materials from green tobacco is also known in the art. For example, in U.S. Pat. No. 940,181 extract is pressed from green tobacco and applied to other tobacco to alter the qualities of the latter. U.S. Pat. No. 1,209,327 describes an improvement of the above process and further suggests removal of nicotine from the extract. In U.S. Pat. No. 4,018,234 freshly harvested tobacco is pressed by light non-abrasive contact with an absorbent surface to reduce its surface lipid content.
In U.S. Pat. No. 3,845,774 curing is effected by homogenizing yellowed tobacco leaf, incubating the homogenized material and then curing the mass as it is dried. The leaf characteristics may be manipulated during this homogenization curing method by chemical, physical or biological means.
It has now been discovered that by expressing protoplasmic juices from green tobacco, the chemical composition of the tobacco can be altered. Moreover, it has been discovered that tobacco from which the juices have been expressed can be artifically cured and can be further processed without the need for stemming or homogenization.